In a medium bowl, whisk together water, peanut butter and molasses until well combined and smooth. Pour mixture into the dry ingredients and stir to form a stiff dough. Scoop out dough to a lightly floured surface and knead until smooth, adding additional whole-wheat flour as needed to keep it from sticking to your hands. Cover dough and let rest for 5 to 10 minutes.

Lightly flour your working surface and roll out dough to roughly 1/4" thick. Cut out shapes using your favorite cutters and place on baking sheets lined with parchment paper. Continue re-rolling and cutting the dough until it is all used up. Place baking sheets into the oven and bake until lightly browned, rotating the sheets halfway through, about 20 to 30 minutes. Remove from the oven and transfer biscuits to a wire rack to cool completely.